When transferring power from a drive means, such as a motor or engine, to a driven means, such as a pump compressor or turbine, a rotatable shaft is often provided to connect the two. Furthermore, it is often advantageous to provide two separate shafts, one being a driving shaft and one being a driven shaft, to facilitate manufacture and repair. In using two shafts, a coupler is required. If the coupler is not relatively easy to retract or remove, repairing the system may be hindered.
Therefore, a simple, low cost, easy to retract or remove coupler would be of great benefit in situations in which two shafts need to be coupled. The present invention is directed to providing such a coupler and overcoming one or more of the above problems.